The food processing industry is continually developing new approaches to preparing food products and particularly food items derived from animal products for human consumption. Generally, these approaches attempt to improve the overall consistency and quality of food products delivered to the consumer. In particular, food processors adopt various methods and systems to improve the flavor, shelf life, appearance, and nutrition of food products.
One approach to processing food products, and animal products in particular, places the animal product in a tumbler filled with a saline solution. The ham processing industry uses a tumbler to dramatically increase the water content of ham, sometimes as much as one hundred percent from its pre-tumbling weight. Another approach utilizes a tumbler partially evacuated and filled with a saline solution for alternately exposing the animal products to the saline solution and partial vacuum. The hydration achieved using a vacuum tumbler is significantly lower than the hydration achieved when processing hams using a conventional tumbler.
Overall consistency and quality of certain fish products may be improved dramatically by similar food preparation processes. In particular, the processing of catfish in a tumbler may result in a reduction in the "off-flavor" problem that historically has limited the expansion of the cultured catfish industry. It is estimated that ten percent of any harvest of "good" catfish is off-flavor. During the late summer as much as eighty percent of the available pond product is sufficiently off-flavor to interfere with commercial use. At least one source of the off-flavor in catfish tissue is geosmin (C.sub.12 H.sub.22 O), which is a volatile alcohol deposited by the metabolic process of the fish in the lipid fraction of the body. Several previous approaches, including tumbling and vacuum tumbling, have attempted to remove geosmin from catfish tissue to enhance flavor, reduce the overall fat content of the fish, and improve its shelf life.
Previous processing systems have experienced some limited success in enhancing the overall quality and consistency of animal products. These previous approaches, however, have not adequately identified and extracted the major components leading to low quality animal products and bacterial contamination. Furthermore, specific approaches in the catfish industry have not sufficiently solved the off-flavor problem of cultured catfish, especially the off-flavor present in larger and higher fat content fish caught during the late summer. The disadvantages of prior methods and systems for processing animal products have severely impaired the expansion of the cultured catfish industry.